• Inter-decadal change in sablefish, Anoplopoma fimbria, growth and maturity in the Northeast Pacific Ocean

      Howard, Katy B.; Adkison, Milo D.; Hillgruber, Nicola; Sigler, Michael F. (2008-08)
      Errors in growth and maturity estimates can drastically affect the spawner-per-recruit threshold used to recommend commercial fish catch quotas. Growth and maturity parameters for Alaskan sablefish, Anoplopoma fimbria, have not been updated for stock assessment purposes for 20 years, even though sablefish aging has continued. In this study, the old length-stratified data set (1981-1993) was updated and corrected for bias. In addition, newer, randomly collected samples (1996-2004) were analyzed, and new length-at-age, weight-at-age, and maturity-at-age and length parameters were estimated. A comparison of the two datasets showed that in recent years, sablefish are growing larger and maturing later and that growth and maturity differ somewhat among regions. The updated growth information improves data fits in the sablefish stock assessment model. It also provides results that are biologically reasonable. These updated and improved estimates of sablefish growth and maturity help ensure the continued proper management of this commercially important species in Alaskan waters.